This invention is in the field of infrared (thermal) detectors. Such detectors are undergoing increasing civilian, police, and military uses nowadays. Some infrared detectors can operate only if cooled to cryogenic temperatures, or can only operate efficiently at these temperatures. Unfortunately, this creates a possible problem for some users; in the case of a military user, for example, an enemy equipped with a thermal viewer can "see" the military user's detector because of the "black hole" that its cooled detector creates in a scene. The present invention solves this problem.